GB1379041A - Stuffer box crimping apparatus for crimping yarns - Google Patents

Abstract

1379041 Crimping yarns PLATT INTERNATIONAL Ltd 5 Sept 1972 [9 Sept 1971] 42150/71 Heading D1F A stuffer box crimping apparatus comprises ultrasonic sensing means which detects unacceptable change in the position of a plug of crimped yarn in the stuffer chamber and generates a corresponding control signal whereby the speed of feed into or withdrawal of yarn from the chamber is correctively adjusted. In the crimper shown in Fig. 1, when the head of the plug is below an emitter 23 and detector 27 both the beams from electrically actuated, ultrasonic pressure wave emitters 22 and 23 strike detectors 26 and 27 and produce output signals which are applied to a circuit 30 to operate a speed control unit 31 to reduce the speed of delivery rollers 28, 29. As the plug then rises and the beams are successively interrupted the collective change in output signal from the detectors operates the unit 31 to increase the speed of delivery roller 28, 29. Subsequent fall in the level of the plug in the passage 8 beyond both emitters results in a corrective speed reduction. Alternatively the speed control may be applied to the crimping rollers 12 and 13. In another crimper, Fig. 2 (not shown) a single ultrasonic beam when interrupted by the plug causes a detector to generate a signal which is proportional to the fibre density of the plug and initiate corrective speed control. In the apparatus of Fig. 3, the aligned emitter 22 and detector 26 are carried on a reciprocating carriage 64 so that the the control signal from detector 26 is proportional to the average fibre density of a ply of yarn scanned by the ultrasonic beam along a length determined by slots 60, 62, in plates 6 and 7 forming sides of the stuffing chamber.